The Administrative and Clinical Core is designed: 1) To continue to follow participants in Cohort 1 and Cohort 2 (the subjects recruited during past funding cycles) by annual administration of a semi-structured interview to each subject and their collateral. 2) To screen and recruit a third group of subjects that will comprise Cohort 3 and evaluate them annually with the same semi-structured interview administered to Cohorts 1 & 2, 3) To schedule participants from Cohorts 1-3 for all necessary evaluations by the four subprojects, 4) to draw blood from participants so that the Genetic Core can obtain DNA for genetic analyses, 5) To supervise and coordinate transmission of data from each Core and project to the Central Database, 6) To provide clinical evaluations on all subjects who progress to dementia to determine which participants meet clinical criteria for Alzheimer's disease (AD) and to provide a clinical resource for all subjects who are concerned about their memory and are seeking clinical input, and 7) To obtain autopsy approval from participants and coordinate the acquisition of autopsy tissue for the Neuropathology Core.